Antibiotics bactericidal activity

FIGURE 103-7. Killing curve depicting the effect of concentration on antibiotic bactericidal activity. CPU = colony-forming units MIC = minimal Inhibitory concentration. 0.25-64 times the MIC the organism tested was P. aeruginosa ATCC 27853. (From ref 51.)... 

Pharmacology Meropenem is a broad-spectrum carbapenem antibiotic. The bactericidal activity of meropenem results from the inhibition of cell-wall synthesis. Meropenem readily penetrates the cell wall of most gram-positive and gram-negative bacteria to reach penicillin-binding-protein (PBP) targets. 

Pharmacology This product is a formulation of imipenem, a thienamycin antibiotic, and cilastatin sodium, the inhibitor of the renal dipeptidase, dehydropeptidase-1, which is responsible for the extensive metabolism of imipenem when it is administered alone. Cilastatin prevents the metabolism of imipenem, increasing urinary recovery and decreasing possible renal toxicity. The bactericidal activity of imipenem results from the inhibition of cell-wall synthesis, related to binding to penicillin-binding proteins (PBP). 

The aminoglycosides include streptomycin, gentamicin, tobramycin, netilmicin, kanamycin, amikacin, sisomicin, neomycin, paromomycin and others. Those are bactericidal antibiotics. This bactericidal activity is concentration dependent in contrast to the... 

Mechanism of Action An antibiotic that alters cell membrane permeability in susceptible microorganisms. Therapeutic Effect Bactericidal activity Pharmacokinetics Negligible absorption. Protein binding low. Excreted in urine. Poor removal in hemodialysis. Half-life 6 hr. 

The bacteriostatic activity which is inhibition of growth and multiplication of bacteria and bactericidal activity, which is bacterial death, is induced by certain types of antibiotics. Cytotoxic action is selective for invading cancer cells and altering them without affecting the host cells. 

Cefixime is an orally active third-generation cephalosporin antibiotic which has marked in-vitro bactericidal activity against a wide variety of gram positive and negative organisms. It is indicated for the treatment of urinary tract, infection, respiratory tract infection and biliary tract infection etc. 

They have bactericidal activity against gram negative bacteria only and are low molecular cationic polypeptide antibiotics. 

Chloramphenicol, a broad spectrum antibiotic, is active not only against bacteria but also against other microorganisms, such as rickettsiae. Chloramphenicol has excellent activity against anaerobes. The drug is either bactericidal or (more commonly) bacteriostatic, depending on the organism. 

Because of their broad potent bactericidal activity the fluoroquinolone antibiotics are also an appropriate topical therapy for nongonococcal hyperacute conjimc-tivitis. Topical moxifloxacin or gatifloxacin should be administered initially in a dose of two drops every hour. 

Blaser J, Stone BB, Groner MC, Zinner SH. Comparative stndy with enoxacin and netilmicin in a pharmacodynamic model to determine importance of ratio of antibiotic peak concentration to MIC for bactericidal activity and emergence of resistance. Antimicrob Agents Chemother 1987 31(7) 1054-60. 

Daptomycin is a novel lipopeptide antibiotic, an inhibitor of lipoteichoic acid synthesis, with potent bactericidal activity against most clinically important Gram-positive bacteria, including resistant strains (1,2). 

Cell wall agents, such as glycopeptides, have concentration-independent bactericidal activity, and the time over which the antibiotic serum concentration persists over the minimal inhibitory concentration of the pathogen is a main pharmacodynamic determination of the outcome. In a two-way, randomized, open, two-period, crossover study in 10 healthy adults, teicoplanin given in two 200 mg doses intramuscularly produced steady-state trough concentrations even higher than those after once-daily intravenous administration of 400 mg (3). Conversion from intravenous to intramuscular administration may therefore allow better compliance with preserved efficacy. Intramuscular teicoplanin was well tolerated. Adverse effects reported were mild local pain for 2-3 hours, headache, and backache. 

The therapeutic objectives in treating bacterial keratitis are the rapid elimination of the pathogen from the external eye and gaining control of the inflairunatory response. Optimally, broad-spectrum, antibacterial solutions should be used for topical antibiosis. The rapid elution of topical solutions from the ocular surface demands that high-concentration aqueous preparations of antibiotics be administered at 30-60 min intervals. The dmg selected should exhibit concentration-dependent, bactericidal activity that is, the rate... 

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